Four-Loop Gauge and Three-Loop Yukawa Beta Functions in a General Renormalizable Theory

Two Loop QCD Vertices and Three Loop MOM beta functions

Supergraph Techniques and Two-Loop Beta-Functions for Renormalizable and Non-Renormalizable Operators

We present a construction kit for calculating two-loop beta functions in N =1 supersymmetric theories for the operators of the superpotential using supergraph techniques. In particular, it allows to compute the beta functions for every desired, even higher dimensional, operator of the superpotential from the wavefunction renormalization constants of the theory. We apply this method to calculate...

Two-loop scalar self-energies and pole masses in a general renormalizable theory with massless gauge bosons

I present the two-loop self-energy functions for scalar bosons in a general renormalizable theory, within the approximation that vector bosons are treated as massless or equivalently that gauge symmetries are unbroken. This enables the computation of the two-loop physical pole masses of scalar particles in that approximation. The calculations are done simultaneously in the massindependent MS, D...

Three - loop Three - Linear Vertices and Four - Loop m̃om β functions in massless QCD

In this paper we present a full set of 2-and 3-point functions for massless QCD at three-loop order in the ms scheme. The vertex functions are evaluated at the asymmetric point with one vanishing momentum. These results are used to relate the ms coupling constant to that of various momentum subtraction (mom) renormalization schemes at three-loop order. With the help of the known four-loop ms β-...

Four and Three Loop Calculations in QCD : Theory and Applications ∗

The talk briefly reviews the current state of the art in doing multiloop QCD calculations in a completely analytic way. In particular, we discuss recent analytical calculations of 4-loop O(α 3 s) gluino contribution to R(s) and its implications to Γ tot (Z → hadrons) and Γ(τ − → ν τ + hadrons);